I wondered why Kibblewhite seem to no longer list the aluminium tube pushrods, could it be a sign, it is a risk I can not take.
I guess pulling the engine back out will give time to find Viton KW valve stem seals and remove the AE piston circlips to see if SS replacements are a tighter fit.
The carnage pic of the FB engine were very sobering, when it was posted initially with the top end removed (obvious piston seizing) I thought timing side oil seals failing (@ 600 miles) , not the gear and shaft shearing off for no oil supply, yikes.
Did a failing pushrod initiate all that.